Always some amount of water vapor is airborne. At the same time distinguish absolute and relative humidity. The first is the density of water vapor in air at a certain temperature. But in everyday life this indicator is not of a particular interest. Quite another matter - relative humidity.
It is required to you
- - hygrometer;
- - thermometer;
- - gauze;
- - glass pile;
- - hours.
Instruction
1. Relative humidity – the attitude of the water vapor which is contained in air towards their greatest possible value. It is the important component influencing all live. The high humidity can become the cause of respiratory diseases at people and animals. At too low there is an increased fatigue, deterioration in sight, irritation of mucous membranes. It is made humidity is of particular importance for houseplants which many species are tropical and need the increased its concentration.
2. Relative humidity is determined by means of a hygrometer. But it is possible to do also without it. Take air temperature the mercury thermometer, write down its indications. Moisten with water a piece of a gauze and wrap up in it a thermometer head. Consider that it should not be on a draft or near the fan. In this case evaporation accelerates, the result will be incorrect. In 10 minutes take readings again. From the first value take away the second. Now you will need psikhrometrichesky tables. Find the value corresponding to the indication of your dry thermometer in an extreme left column. Move from it to the right. The top horizontal line - the difference of indications. Find the value. Move on this column down. Number on crossing of a line and column - required value of relative humidity.
3. In everyday life, as a rule, exact determination of relative air humidity is not required. Pour cold water in a glass pile. Place it at several o'clock in the fridge. During this time water temperature will fall up to 3-5 degrees.
4. Move a pile in the room in which you want to determine relative air humidity. Do not put it near heating devices. Observe a surface of walls. At first there is a condensation of water vapor on cold glass - it misted over. But if five minutes were enough that moisture evaporated, so air in the room dry, no more than 25% of humidity. If the pile walls which still misted over – humidity average, 40-60%. In five minutes on the surface of glass streamlets were formed. Relative humidity in 80-90%, i.e. high.